Yes...inbreeding should not be done. Whether you would get something wrong with the first clutch or not, I am not sure. I would assume it is possible.

We rescued a pair and found out the female was gravid. They had been bred multiple times, since they were housed together, and later on we found out that they had been purchased by the previous owner from the same clutch....which means they were brother and sister. From our first clutch, my friend and business partner at the time had three gimpy baby girls and I had two.

It is so not necessary and so easy to avoid, but people are not doing their research. Thank you for wondering and actually coming out and asking.